This work was supported by the NINDS (grant #1R01NS079702 to A.C.L.) and the SURP Program at Thomas Jefferson University (M.M.).

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יש לנו מה למסור.

כפונקציה נשימה נפגעת בשני SCI הטראומתי וALS, פיתוח טיפולים המתמקדים בנשימה ובאופן ספציפי עצבוב סרעפת קליני רלוונטיים 5,6. כדי ללמוד לתפקד בדרכי הנשימה באופן מקיף, יש להשתמש בשיטת גישה משולבת. CMAPs למדוד את מידת העצבוב התפקודי של הסרעפת בדרך של גירוי עצב הסרעפת חיצונ?...

טרשת לרוחב amyotrophic (ALS) היא מחלה הנוירון המוטורי מתישה הקשורים לאובדן של שני נוירונים מוטוריים העליונים ותחתונים ושיתוק שריר הסוגר. לאחר האבחון, הישרדות חולה היא בממוצע רק 2-5 שנים 1. אובדן הנוירון מוטורי (PhMN) הסרעפת הוא מרכיב קריטי של פתוגנזה של ALS. חולי סופו של דבר למות כתוצאה מאובדן עצבוב PhMN של הסרעפת, השריר העיקרי של ההשראה 2,3. פגיעה בחוט השדרה טראומטית (SCI) היא גם בעיה רצינית עם קשיי הנשימה קשורים. כ -12,000 מקרים חדשים של SCI להתרחש בכל שנה 4 בשל נזק טראומטי לחוט השדרה. למרות ההטרוגניות מחלה ביחס למיקום, סוג וחומרה, רובם של המקרים SCI כרוכים טראומה לחוט השדרה הצווארי, אשר לעתים קרובות תוצאות פשרה נשימה מתישה ומתמשכת. בנוסף לALS וSCI, מערכת עצבים מרכזית אחרת יכולות להיות קשורות למחלות (CNS) wתפקוד לקוי של ה- i סרעפתי נשימה 5,6. עצב הסרעפת הוא עצב מוטורי efferent שמעצבב חמי-סרעפת ipsilateral ושמקורו מגופי תא PhMN ממוקמים ברמות C3-C5 של חוט השדרה הצווארי ipsilateral. פלט PhMN נשלט על ידי יורד קלט bulbospinal מגזע המוח באזור המכונה הקבוצה מקורי הגחון הנשימה (rVRG) 7. מעגל rVRG-PhMN-הסרעפת הוא מרכזי לשליטה של ​​נשימת שאיפה, כמו גם התנהגויות סרעפת אינן נשימתית אחרות. פציעות שונות טראומטיות והפרעות ניווניות המשפיעות על מעגלים זה יכולים להוביל לירידה עמוקה בתפקוד נשימה ואיכות חיי מטופל. יורד קלט לPhMNs מהישרדות rVRG, PhMN, יושרת עצב הסרעפת והעצבוב נכון בצומת העצבית-שרירית סרעפת (NMJ) הם כל נחוצים לתפקוד סרעפת נורמלי. לכן חשוב להעסיק טכניקות שכמותית יכול להעריך מעגל זה in vivo במודלים של מכרסמים של ALS, SCI ומחלות של מערכת העצבים המרכזית אחרות. עם פרוטוקול זה, המטרה היא לתאר בכלים ניסיוניים להערכת עצבוב PhMN של הסרעפת בשני אלקטרו והרמות מורפולוגיים. פוטנציאל פעולת שרירים מתחם (CMAPs) נרשם על ידי גירוי כל האקסונים הנוירון מוטורי efferent של עצב מוטורי נתון ולאחר מכן לנתח את תגובת שלילת קוטביות שהושרו של myofibers היעד. טכניקה זו יכולה לשמש in vivo בחולדות ועכברים מורדמים לכמת עצבוב תפקודי של חמי-הסרעפת על ידי PhMNs 8. בשל העובדה שCMAPs מייצג הקלטה בו זמנית של כל (רב לפחות או / ביותר) myofibers של כל חמי-סרעפת, זה שימושי גם לבחון את פנוטיפים של אקסונים פרט מנוע וmyofibers בNMJ הסרעפת כדי לעקוב אחר מחלה - ושינויים מורפולוגיים טיפול רלוונטי כגון חלקי ומכלוליםdenervation te, צמיחה והתחדשות reinnervation. זה יכול להיות מושלם באמצעות אימונוהיסטוכימיה כל הר (IHC) של הסרעפת, ואחרי הערכת מורפולוגיות מפורטת של NMJs הבודד לאורך השריר 9. שילוב CMAPs וניתוח NMJ מספק גישה רבת עוצמה לכמותית לומד עצבוב סרעפת במודלים של מכרסמים של המחלה של מערכת העצבים המרכזית וPNS.

<table border="0" cellpadding="0" cellspacing="0" width="902">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Paraformaldehyde</td>
			<td style="width:273px;">Fisher</td>
			<td style="width:131px;">T353-500</td>
			<td style="width:167px;">Make 10% solution first in de-ionized distilled water; make 4% with 1X PBS, adjust pH to 7.4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">1X Phosphate Buffered Saline, pH 7.4</td>
			<td style="width:273px;">Invitrogen</td>
			<td style="width:131px;">10010049</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">2% Bovine serum albumin (2% BSA)</td>
			<td style="width:273px;">Sigma-Aldrich</td>
			<td style="width:131px;">A3059-100g</td>
			<td>Dissolve 2g BSA into 100mL of 1X PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">0.2% Triton X100 in 2% BSA/PBS (Blocking Buffer)</td>
			<td style="width:273px;">Sigma-Aldrich</td>
			<td style="width:131px;">T9284-100mL</td>
			<td>Dissolve 0.2ml/100mL 2% BSA/PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">0.1M Glycine</td>
			<td style="width:273px;">Sigma-Aldrich</td>
			<td style="width:131px;">G-7126</td>
			<td>Add 0.185g to 25mL of 2% BSA/PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">&#945;-bungarotoxin</td>
			<td style="width:273px;">Invitrogen</td>
			<td style="width:131px;">T1175</td>
			<td>Concentration 1:400</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">SMI-312&#160;</td>
			<td style="width:273px;">Sternberger Monoclonals</td>
			<td style="width:131px;">SMI312</td>
			<td>Concentration 1:1,000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">SV2</td>
			<td style="width:273px;">Developmental Studies Hybridoma Bank</td>
			<td style="width:131px;">SV2-Supernatant</td>
			<td>Concentration 1:10</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">FITC goat anti-mouse IgG1</td>
			<td style="width:273px;">Roche</td>
			<td style="width:131px;">3117731001</td>
			<td>Concentration 1:100</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Silicone rubber</td>
			<td style="width:273px;">Sylgard, Dow Corning</td>
			<td style="width:131px;">Part # 184</td>
			<td>Follow instructions that come with kit: can use multiple sized culture dish (30mm, 60mm, 100mm) depending on needs</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Vectashield fluorescent mounting medium</td>
			<td style="width:273px;">Vector laboratories</td>
			<td style="width:131px;">H-1000</td>
			<td>This is not a hard-set medium. You will need to secure the cover slip with clear nail polish.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Small Spring Scissors</td>
			<td style="width:273px;">Fine Science Tools</td>
			<td style="width:131px;">15002-08</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Dissection forceps</td>
			<td style="width:273px;">Fine Science Tools</td>
			<td style="width:131px;">11295-51</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Software for CMAP recordings</td>
			<td style="width:273px;">Scope 3.5.6; ADI</td>
			<td style="width:131px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Disk surface electrodes</td>
			<td style="width:273px;">Natus neurology</td>
			<td style="width:131px;">019-409000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Subdermal needle electrodes</td>
			<td style="width:273px;">Natus neurology</td>
			<td style="width:131px;">019-453100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Conductive gel</td>
			<td style="width:273px;">Aquasonic&#160;</td>
			<td style="width:131px;">122-73720</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:332px;">Stimulator/recording system for CMAP recordings</td>
			<td style="width:273px;">ADI Powerlab 8SP stimulator&#160;</td>
			<td style="width:131px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Amplifier for CMAP recordings</td>
			<td style="width:273px;">BioAMP</td>
			<td style="width:131px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

functional and morphological assessment of diaphragm innervation by phrenic motor neurons

This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and morphological levels. Compound muscle action potential (CMAP) recording following phrenic nerve stimulation can be used to quantitatively assess functional diaphragm innervation by PhMNs of the cervical spinal cord in vivo in anesthetized rats and mice. Because CMAPs represent simultaneous recording of all myofibers of the whole hemi-diaphragm, it is useful to also examine the phenotypes of individual motor axons and myofibers at the diaphragm NMJ in order to track disease- and therapy-relevant morphological changes such as partial and complete denervation, regenerative sprouting and reinnervation. This can be accomplished via whole-mount immunohistochemistry (IHC) of the diaphragm, followed by detailed morphological assessment of individual NMJs throughout the muscle. Combining CMAPs and NMJ analysis provides a powerful approach for quantitatively studying diaphragmatic innervation in rodent models of CNS and PNS disease.

Sprague-Dawley חולדות מבוגרות קיבלו גם laminectomy בלבד (שליטה ללא פגע) או חמי-חבלה חד צדדית SCI ברמת חוט השדרה C4 10-12. בשעת 5 שבועות לאחר ניתוח, שיא משרעת מבנה מפת צבעים נרשמו מחם-סרעפת ipsilateral לאתר laminectomy / פציעה הופחתה באופן משמעותי בחולדות SCI (איור 2 ג) בהשוואה לשליטת lamin...

Watch this Scientific Journal Video about Functional and Morphological Assessment of Diaphragm Innervation by Phrenic Motor Neurons at JoVE.com

Functional and Morphological Assessment of Diaphragm Innervation by Phrenic Motor Neurons

Compound muscle action potential recording quantitatively assesses functional diaphragm innervation by phrenic motor neurons. Whole-mount diaphragm immunohistochemistry assesses morphological innervation at individual neuromuscular junctions. The goal of this protocol is to demonstrate how these two powerful methodologies can be used in various rodent models of spinal cord disease.

הערכה תפקודית ומורפולוגי של סרעפת עצבוב על ידי סרעפת מנוע נוירונים

This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and ...

functional-morphological-assessment-diaphragm-innervation-phrenic

Research

JoVE Journal

Neuroscience

17.4K Views.  Sidney Kimmel Medical College at Thomas Jefferson University. Compound muscle action potential recording quantitatively assesses functional diaphragm innervation by phrenic motor neurons. Whole-mount diaphragm immunohistochemistry assesses morphological innervation at individual neuromuscular junctions. The goal of this protocol is to demonstrate how these two powerful methodologies can be used in various rodent models of spinal cord disease. 

Video: Functional and Morphological Assessment of Diaphragm Innervation by Phrenic Motor Neurons

Physiological, Morphological and Neurochemical Characterization of Neurons Modulated by Movement

The role of individual neurons and their function in neuronal circuits is fundamental to understanding the neuronal mechanisms of sensory and motor functions. Most investigations of sensorimotor mechanisms rely on either examination of neurons while an animal is static1,2 or record extracellular neuronal activity during a movement.3,4 While these studies have provided the fundamental background for sensorimotor function, they either do not evaluate functional information which occurs during a movement or are limited in their ability to fully characterize the anatomy, physiology and neurochemical phenotype of the neuron. A technique is shown here which allows extensive characterization of individual neurons during an in vivo movement. This technique can be used not only to study primary afferent neurons but also to characterize motoneurons and sensorimotor interneurons. Initially the response of a single neuron is recorded using electrophysiological methods during various movements of the mandible followed by determination of the receptive field for the neuron. A neuronal tracer is then intracellularly injected into the neuron and the brain is processed so that the neuron can be visualized with light, electron or confocal microscopy (Fig. 1). The detailed morphology of the characterized neuron is then reconstructed so that neuronal morphology can be correlated with the physiological response of the neuron (Figs. 2,3). In this communication important key details and tips for successful implementation of this technique are provided. Valuable additional information can be determined for the neuron under study by combining this method with other techniques. Retrograde neuronal labeling can be used to determine neurons with which the labeled neuron synapses; thus allowing detailed determination of neuronal circuitry. Immunocytochemistry can be combined with this method to examine neurotransmitters within the labeled neuron and to determine the chemical phenotypes of neurons with which the labeled neuron synapses. The labeled neuron can also be processed for electron microscopy to determine the ultrastructural features and microcircuitry of the labeled neuron. Overall this technique is a powerful method to thoroughly characterize neurons during in vivo movement thus allowing substantial insight into the role of the neuron in sensorimotor function.

A technique is described to quantify the in vivo physiological response of mammalian neurons during movement and correlate the physiology of the neuron with neuronal morphology, neurochemical phenotype and synaptic microcircuitry.

אפיון פיזיולוגיים, מורפולוגי והעצבית של נוירונים מווסתת על ידי תנועת

The role of individual neurons and their function in neuronal circuits is fundamental to understanding the neuronal mechanisms of sensory and motor ...

Targeted Labeling of Neurons in a Specific Functional Micro-domain of the Neocortex by Combining Intrinsic Signal and Two-photon Imaging

In the primary visual cortex of non-rodent mammals, neurons are clustered according to their preference for stimulus features such as orientation1-4, direction5-7, ocular dominance8,9 and binocular disparity9. Orientation selectivity is the most widely studied feature and a continuous map with a quasi-periodic layout for preferred orientation is present across the entire primary visual cortex10,11. Integrating the synaptic, cellular and network contributions that lead to stimulus selective responses in these functional maps requires the hybridization of imaging techniques that span sub-micron to millimeter spatial scales. With conventional intrinsic signal optical imaging, the overall layout of functional maps across the entire surface of the visual cortex can be determined12. The development of in vivo two-photon microscopy using calcium sensitive dyes enables one to determine the synaptic input arriving at individual dendritic spines13 or record activity simultaneously from hundreds of individual neuronal cell bodies6,14. Consequently, combining intrinsic signal imaging with the sub-micron spatial resolution of two-photon microscopy offers the possibility of determining exactly which dendritic segments and cells contribute to the micro-domain of any functional map in the neocortex. Here we demonstrate a high-yield method for rapidly obtaining a cortical orientation map and targeting a specific micro-domain in this functional map for labeling neurons with fluorescent dyes in a non-rodent mammal. With the same microscope used for two-photon imaging, we first generate an orientation map using intrinsic signal optical imaging. Then we show how to target a micro-domain of interest using a micropipette loaded with dye to either label a population of neuronal cell bodies or label a single neuron such that dendrites, spines and axons are visible in vivo. Our refinements over previous methods facilitate an examination of neuronal structure-function relationships with sub-cellular resolution in the framework of neocortical functional architectures.

A method is described for labeling neurons with fluorescent dyes in predetermined functional micro-domains of the neocortex. First, intrinsic signal optical imaging is used to obtain a functional map. Then two-photon microscopy is used to label and image neurons within a micro-domain of the map.

תיוג ממוקד של תאי עצב בתחומים ספציפיים מייקר פונקציונליים של הניאוקורטקס ידי שילוב אותות פנימיים והדמית שני פוטונים

In the primary visual cortex of non-rodent mammals, neurons are clustered according to their preference for stimulus features such as orientation1-4, ...

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.
This extracellular technique has advantages. First, extracellular electrodes can stimulate and record neurons through the sheath5, so it does not need to be removed. Thus, neurons will be healthier in extracellular experiments than in intracellular ones. Second, if ganglia are rotated by appropriate pinning of the sheath, extracellular electrodes can access neurons on both sides of the ganglion, which makes it easier and more efficient to identify multiple neurons in the same preparation. Third, extracellular electrodes do not need to penetrate cells, and thus can be easily moved back and forth among neurons, causing less damage to them. This is especially useful when one tries to record multiple neurons during repeating motor patterns that may only persist for minutes. Fourth, extracellular electrodes are more flexible than intracellular ones during muscle movements. Intracellular electrodes may pull out and damage neurons during muscle contractions. In contrast, since extracellular electrodes are gently pressed onto the sheath above neurons, they usually stay above the same neuron during muscle contractions, and thus can be used in more intact preparations.
To uniquely identify motor neurons for a motor pool (in particular, the I1/I3 muscle in Aplysia) using extracellular electrodes, one can use features that do not require intracellular measurements as criteria: soma size and location, axonal projection, and muscle innervation4,6,7. For the particular motor pool used to illustrate the technique, we recorded from buccal nerves 2 and 3 to measure axonal projections, and measured the contraction forces of the I1/I3 muscle to determine the pattern of muscle innervation for the individual motor neurons.
We demonstrate the complete process of first identifying motor neurons using muscle innervation, then characterizing their timing during motor patterns, creating a simplified diagnostic method for rapid identification. The simplified and more rapid diagnostic method is superior for more intact preparations, e.g. in the suspended buccal mass preparation8 or in vivo9. This process can also be applied in other motor pools10,11,12 in Aplysia or in other animal systems2,3,13,14.

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.

Extracellularly זיהוי תאי עצב מוטורי לשריר בברכת מוטור<em&gt; Aplysia californica</em

In animals with large  identified neurons (e.g. mollusks), analysis of motor pools is done using  intracellular techniques1,2,3,4. Recently,  we developed ...

Retrograde Neuroanatomical Tracing of Phrenic Motor Neurons in Mice

Phrenic motor neurons are cervical motor neurons originating from C3 to C6 levels in most mammalian species. Axonal projections converge into phrenic nerves innervating the respiratory diaphragm. In spinal cord slices, phrenic motor neurons cannot be identified from other motor neurons on morphological or biochemical criteria. We provide the description of procedures for visualizing phrenic motor neuron cell bodies in mice, following intrapleural injections of cholera toxin subunit beta (CTB) conjugated to a fluorophore. This fluorescent neuroanatomical tracer has the ability to be caught up at the diaphragm neuromuscular junction, be carried retrogradely along the phrenic axons and reach the phrenic cell bodies. Two methodological approaches of intrapleural CTB delivery are compared: transdiaphragmatic versus transthoracic injections. Both approaches are successful and result in similar number of CTB-labeled phrenic motor neurons. In conclusion, these techniques can be applied to visualize or quantify the phrenic motor neurons in various experimental studies such as those focused on the diaphragm-phrenic circuitry.

Here, we describe a protocol for identifying phrenic motor neurons in mice after intrapleural delivery of fluorophore conjugated cholera toxin subunit beta. Two techniques are compared to inject the pleural cavity: transdiaphragmatic versus transthoracic approaches.

עקיבה Neuroanatomical רטרוגרדית של הסרעפת מוטורי לגלוקוז בעכברים

Phrenic motor neurons are cervical motor neurons originating from C3 to C6 levels in most mammalian species. Axonal projections converge into phrenic ...

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea

Cochlear inner hair cells (IHCs) transmit acoustic signals to spiral ganglion neurons (SGNs) through ribbon synapses. Several experimental studies have indicated that hair cell synapses may be the initial targets in sensorineural hearing loss (SNHL). Such studies have proposed the concept of cochlear &#34;synaptopathy&#34;, which refers to alterations in ribbon synapse number, structure, or function that result in abnormal synaptic transmission between IHCs and SGNs. While cochlear synaptopathy is irreversible, it does not affect the hearing threshold. In noise-induced experimental models, restricted damage to IHC synapses in select frequency regions is employed to identify the environmental factors that specifically cause synaptopathy, as well as the physiological consequences of disturbing this inner ear circuit. Here, we present a protocol for analyzing cochlear synaptic morphology and function at a specific frequency region in adult mice. In this protocol, cochlear localization of specific frequency regions is performed using place-frequency maps in conjunction with cochleogram data, following which the morphological characteristics of ribbon synapses are evaluated via synaptic immunostaining. The functional status of ribbon synapses is then determined based on the amplitudes of auditory brainstem response (ABR) wave I. The present report demonstrates that this approach can be used to deepen our understanding of the pathogenesis and mechanisms of synaptic dysfunction in the cochlea, which may aid in the development of novel therapeutic interventions.

This manuscript describes an experimental protocol for evaluating the morphological characteristics and functional status of ribbon synapses in normal mice. The present model is also suitable for noise-induced and age-related cochlear synaptopathy-restricted models. The correlative results of previous mouse studies are also discussed.

מורפולוגית ופונקציונלית הערכה של הסרט סינפסות בתדר ספציפי אזורים של העכבר שבלול

Cochlear inner hair cells (IHCs) transmit acoustic signals to spiral ganglion neurons (SGNs) through ribbon synapses. Several experimental studies have ...

Conversion of Human Induced Pluripotent Stem Cells (iPSCs) into Functional Spinal and Cranial Motor Neurons Using PiggyBac Vectors

We describe here a method to obtain functional spinal and cranial motor neurons from human induced pluripotent stem cells (iPSCs). Direct conversion into motor neuron is obtained by ectopic expression of alternative modules of transcription factors, namely Ngn2, Isl1 and Lhx3 (NIL) or Ngn2, Isl1 and Phox2a (NIP). NIL and NIP specify, respectively, spinal and cranial motor neuron identity. Our protocol starts with the generation of modified iPSC lines in which NIL or NIP are stably integrated in the genome via a piggyBac transposon vector. Expression of the transgenes is then induced by doxycycline and leads, in 5 days, to the conversion of iPSCs into MN progenitors. Subsequent maturation, for 7 days, leads to homogeneous populations of spinal or cranial MNs. Our method holds several advantages over previous protocols: it is extremely rapid and simplified; it does not require viral infection or further MN isolation; it allows generating different MN subpopulations (spinal and cranial) with a remarkable degree of maturation, as demonstrated by the ability to fire trains of action potentials. Moreover, a large number of motor neurons can be obtained without purification from mixed populations. iPSC-derived spinal and cranial motor neurons can be used for in vitro modeling of Amyotrophic Lateral Sclerosis and other neurodegenerative diseases of the motor neuron. Homogeneous motor neuron populations might represent an important resource for cell type specific drug screenings.

Conversion of Human Induced Pluripotent Stem Cells iPSCs into Functional Spinal and Cranial Motor Neurons Using PiggyBac Vectors

This protocol allows rapid and efficient conversion of induced pluripotent stem cells into motor neurons with a spinal or cranial identity, by ectopic expression of transcription factors from inducible piggyBac vectors.

המרה של האדם המושרה Pluripotent תאי גזע (iPSCs) לתוך השדרה פונקציונלי והגולגולת נוירונים מוטוריים באמצעות שימוש בווקטורים הגולגולתית

We describe here a method to obtain functional spinal and cranial motor neurons from human induced pluripotent stem cells (iPSCs). Direct conversion into ...

3D Kinematic Analysis for the Functional Evaluation in the Rat Model of Sciatic Nerve Crush Injury

Compared to the Sciatic Functional Index (SFI), kinematic analysis is a more reliable and sensitive method for performing functional evaluations of sciatic nerve injury rodent models. In this protocol, we describe a novel kinematic analysis method that uses a three-dimensional (3D) motion capture apparatus for functional evaluations using a rat sciatic nerve crush injury model. First, the rat is familiarized with treadmill walking. Markers are then attached to the designated bone landmarks and the rat is made to walk on the treadmill at the desired speed. Meanwhile, the posterior limb movements of the rat are recorded using four cameras. Depending on the software used, marker tracings are created using both automatic and manual modes and the desired data are produced after subtle adjustments. This method of kinematic analysis, which uses a 3D motion capture apparatus, offers numerous advantages, including superior precision and accuracy. Many more parameters can be investigated during the comprehensive functional evaluations. This method has several shortcomings that require consideration: The system is expensive, can be complicated to operate, and may produce data deviations due to skin shifting. Nevertheless, kinematic analysis using a 3D motion capture apparatus is useful for performing functional anterior and posterior limb evaluations. In the future, this method may become increasingly useful for generating accurate assessments of various traumas and diseases.

We introduce a kinematic analysis method that uses a three-dimensional motion capture apparatus containing four cameras and data processing software for performing functional evaluations during fundamental research involving rodent models.

3D ניתוח קימטי עבור הערכה פונקציונלית במודל חולדה של פציעה העצבים הגיד מעיכה

Compared to the Sciatic Functional Index (SFI), kinematic analysis is a more reliable and sensitive method for performing functional evaluations of ...

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our understanding of the molecular mechanisms underlying axon degeneration remains limited. Injury-induced axon degeneration serves as a simple model to study how severed axons execute their own disassembly (axon death). Over recent years, an evolutionarily conserved axon death signaling cascade has been identified from flies to mammals, which is required for the separated axon to degenerate after injury. Conversely, attenuated axon death signaling results in morphological and functional preservation of severed axons and their synapses. Here, we present three simple and recently developed protocols that allow for the observation of axonal morphology, or axonal and synaptic function of severed axons that have been cut-off from the neuronal cell body, in the fruit fly Drosophila. Morphology can be observed in the wing, where a partial injury results in axon death side-by-side of uninjured control axons within the same nerve bundle. Alternatively, axonal morphology can also be observed in the brain, where the whole nerve bundle undergoes axon death triggered by antennal ablation. Functional preservation of severed axons and their synapses can be assessed by a simple optogenetic approach coupled with a post-synaptic grooming behavior. We present examples using a highwire loss-of-function mutation and by over-expressing dnmnat, both capable of delaying axon death for weeks to months. Importantly, these protocols can be used beyond injury; they facilitate the characterization of neuronal maintenance factors, axonal transport, and axonal mitochondria.

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Here, we provide protocols to perform three simple injury-induced axon degeneration (axon death) assays in Drosophila melanogaster to evaluate the morphological and functional preservation of severed axons and their synapses.

הערכה מורפולוגית ופונקציונלית של Axons וסינפסות שלהם במהלך מוות Axons בדרוסופילה מלאנוסטר

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our ...

Culturing Rat Sympathetic Neurons from Embryonic Superior Cervical Ganglia for Morphological and Proteomic Analysis

Sympathetic neurons from the embryonic rat superior cervical ganglia (SCG) have been used as an in vitro model system for peripheral neurons to study axonal growth, axonal trafficking, synaptogenesis, dendritic growth, dendritic plasticity and nerve-target interactions in co-culture systems. This protocol describes the isolation and dissociation of neurons from the superior cervical ganglia of E21 rat embryos, followed by the preparation and maintenance of pure neuronal cultures in serum-free medium. Since neurons do not adhere to uncoated plastic, neurons will be cultured on either 12 mm glass coverslips or 6-well plates coated with poly-D-lysine. Following treatment with an antimitotic agent (Ara-C, cytosine &#946;-D-arabinofuranoside), this protocol generates healthy neuronal cultures with less than 5% non-neuronal cells, which can be maintained for over a month in vitro. Although embryonic rat SCG neurons are multipolar with 5-8 dendrites in vivo; under serum-free conditions, these neurons extend only a single axon in culture and continue to be unipolar for the duration of the culture. However, these neurons can be induced to extend dendrites in the presence of basement membrane extract, bone morphogenetic proteins (BMPs), or 10% fetal calf serum. These homogenous neuronal cultures can be used for immunocytochemical staining and for biochemical studies. This paper also describes optimized protocol for immunocytochemical staining for microtubule associated protein-2 (MAP-2) in these neurons and for the preparation of neuronal extracts for mass spectrometry.

This paper describes the isolation and culturing of embryonic rat sympathetic neurons from the superior cervical ganglia. It also provides detailed protocols for immunocytochemical staining and for preparing neuronal extracts for mass spectrometric analysis.

חולדה Culturing נוירונים סימפטיים מגנגליה צוואר הרחם מעולה עוברית לניתוח מורפולוגי ופרוטונומי

Sympathetic neurons from the embryonic rat superior cervical ganglia (SCG) have been used as an in vitro model system for peripheral neurons to study ...

Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle

This work outlines functional isolation of motor units (MUs), a standard electrophysiological method for determining characteristics of motor units in hindlimb muscles (such as the medial gastrocnemius, soleus, or plantaris muscle) in experimental rats. A crucial element of the method is the application of electrical stimuli delivered to a motor axon isolated from the ventral root. The stimuli may be delivered at constant or variable inter-pulse intervals. This method is suitable for experiments on animals at varying stages of maturity (young, adult or old). Moreover, this protocol can be used in experiments studying variability and plasticity of motor units evoked by a large spectrum of interventions. The results of these experiments may both augment basic knowledge in muscle physiology and be translated into practical applications. This procedure focuses on the surgical preparation for the recording and stimulation of MUs, with an emphasis on the necessary steps to achieve preparation stability and reproducibility of results.

This method allows the recording of the force of twitch and tetanic contractions and action potentials in three types of motor units in the rat medial gastrocnemius muscle. The functional isolation of a single motor unit is induced by electrical stimulation of the axon.

בידוד פונקציונלי של יחידות מנוע יחיד של שריר גסטרו-קסטרונומיוס חולדה

This work outlines functional isolation of motor units (MUs), a standard electrophysiological method for determining characteristics of motor units in ...